But in places where it has been plentiful, as West Africa and pre Columbian Americas, it was not used as money. In Africa other items were used as money, for example.
I think that an ideal medium of exchange would be something that could be produced in effectively unlimited quantities, but at a cost, and which has a real, practical use. The ability to produce more of it would allow it to keep up with a growing economy, and the practical use would stabilize the price. The best idea I’ve been able to come up with (in the modern world, at least) is doped silicon. I also read a story once where coffee emerged as a de facto medium of exchange, since anyone could harvest the abundantly-growing beans, but it was a lot of work to climb up the mountain to get them, and enough people liked coffee to make it worthwhile.
One of the Hitchhiker’s trilogy mentioned a society of people who had been abandoned on a forested planet. They adopted the leaf as their currency, and IIRC, they were persistently troubled by hyperinflation.
it’s fungible – one bit of gold (in bulk) is exactly the same as another bit; and
it’s completely dividable - half of a gold ingot is worth half of a whole ingot (as opposed to say, horses, where half of a horse isn’t very valuable).